20513137736 has 96 divisors (see below), whose sum is σ = 49486038840. Its totient is φ = 7895688192.

The previous prime is 20513137727. The next prime is 20513137747. The reversal of 20513137736 is 63773131502.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18743252836 + 1769884900 = 136906^2 + 42070^2 .

It is a super-2 number, since 2×20513137736² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20513137736.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134156 + ... + 242948.

Almost surely, 2^20513137736 is an apocalyptic number.

20513137736 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20513137736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24743019420).

20513137736 is an abundant number, since it is smaller than the sum of its proper divisors (28972901104).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20513137736 is a wasteful number, since it uses less digits than its factorization.

20513137736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108863 (or 108852 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 38.

The spelling of 20513137736 in words is "twenty billion, five hundred thirteen million, one hundred thirty-seven thousand, seven hundred thirty-six".